According to the World Health Organization (WHO), arsenic exposure from naturally contaminated well water affects approximately 150 million people worldwide, including millions in the United States. By far, the largest number of exposed individuals reside in Southeast Asia. This R13 grant application seeks support to hold an international conference that will address the most important needs for developing sound remediation strategies. The conference would be held in Hanoi, Vietnam, in May, 2016. The development of the agenda for the proposed conference has involved scientists at Columbia University in New York, the Chulabhorn Research Institute in Bangkok, Thailand, the National Institute of Occupational and Environmental Health (NIOEH) in Hanoi, Vietnam, and the Research Centre for Environmental Technology and Sustainable Development (CETASD) at the Vietnam University of Science in Hanoi. The proposed title of the conference is: Southeast Asia Regional Conference on Groundwater Arsenic: Multi-Disciplinary Approaches to Protecting the Health of the Public. This two day conference would include four half day sessions on the following topics: 1) Earth Science; 2) Health Science; 3) Remediation; and 4) Social and Policy Issues. The anticipated outcome of the conference is the development of a sound regional agenda for minimizing arsenic exposure in vulnerable populations in Vietnam, Thailand, Bangladesh, Cambodia and other neighboring countries with arsenic problems.